内蒙古大沟井寒武纪黑色页岩元素地球化学特征及钒赋存形式

对内蒙古大沟井钒矿床的矿石样品进行了系统的常量和微量元素、X射线粉晶衍射以及显微能谱分析,探讨矿石中钒的赋存形式、形成环境以及保存条件等.研究结果表明,矿石样品中P2 O5含量变化范围为0.81％～6.14％,显示其磷含量普遍较高,反映地层中较为富集磷;样品烧失量的范围为7.75％～41.24％,比较大,反映云母及泥质...

Element Geochemistry and Vanadium Occurrence of the Dagoujing Black Shales,Inner Mongolia

Systematic analysis of ICP-AES, ICP-MS, XRD and EDS was carried out in this paper to discuss the occurrence and distribution of vanadium as well as formation and preservation conditions of the Dagoujing vanadium deposit in Inner Mongolia. The study showed that P₂O₅ contents ranged from 0.81% to 6.14%, and this high phosphor value indicates the enrichment of P in the strata; LOI values ranged from 7.75% to 41.24%, and this high value indicated that mica and argillaceous cement content were high in samples. Vanadium values ranged from 1,015.2×10^-6 to 4,162.0×10^-6, and all the data were much higher than the average composition of the crust. The black shales were classified as normal sedimentary rocks based on the U/Th values; V/Cr, Ni/Co, δU, δCe, Ce/La and V/(V+Ni) values as well as transformation of most of Fe in black shales into pyrite indicated that the black shales in this region formed in a relatively dry, anoxic, H₂S-rich, reducing and close basin condition. Vanadium element in samples mainly occurred in roscoelite, which was in very fine phosphorus shape with polytype 2M₁ and formula K(V,Al,Mg)₂ AlSi₃O₁₀(OH)₂. Occurrence of abundant single or aggregate pyrite in rocks created a favorable condition for vanadium enrichment and preservation in black shales.